The present invention relates generally to automated loading of fuel assemblies for nuclear reactors. It comprises an apparatus for automatically welding end caps to cladding after the fuel pins have been filled and cleaned.
This disclosure relates to the assembly of nuclear fuel assemblies, particularly for use in fast breeder reactors. The present state of the art involves fabrication of fuel assemblies by manual manipulation or by mechanical processes incapable of limiting spread of radioactive contamination to adjoining components and equipment. In such configurations, the fabrication steps are time consuming and create significant radiation contamination control problems.
To achieve flexibility of process steps, radiation contamination control, and efficient fabrication in an apparatus having production capability, the present invention has been directed toward development of a self-contained automated loading system. It allows for system variation and contamination control without degrading production capability. More specifically, the present apparatus permits fabrication and final welding of fuel assemblies by batch processing methods, using equipment which can be physically and environmentally isolated as required.
A large scale system for manufacturing nuclear fuel pellets is disclosed in U.S. Pat. No. 4,174,938. The system includes process components arranged vertically and providing for gravity flow of the product from one component to the next. The various process components are modular and each can be removed without interfering with the others. Physical isolation of the components is provided by appropriate seals and manual access is accomplished through glove ports. Another large scale system for cleaning nuclear fuel elements is shown in U.S. Pat. No. 4,063,962. Batches of fuel elements are suspended vertically and moved through the components of the system. Airlocks and seals are provided to contain contamination.
U.S. Pat. No. 3,828,518 discloses a welding apparatus for closing the end of a fuel rod by use of a rotating electrode head.